eChapters

Introduction

Watershed management has emerged as an important research area in recent years. Understanding the morphology of the catchment is one of the widely used methods for watershed management. Morphometry is the measurement and mathematical analysis of the configuration of the earth’s surface, shape, and dimension of its landforms (Agarwal 1998; Obi Reddy et al., 2002). The study of watershed is very useful in drainage basin evaluation, silt erosion control, flood frequency analysis, watershed prioritization, natural resources management, and conservation (Waikar and Nilawar, 2014). The significance of morphometric analysis is highlighted in the basins that are either un-gauged or difficult to access. The morphometry is usually analyzed through measurement of linear, aerial, relief, gradient of channel network, and contributing ground slope of the basin (Magesh et al., 2012). The hydrological behavior of a basin can be easily determined through the areal parameters (Mahala, 2020.) The evolutionary history of any basin can be best understood through the implication of different relief morphometric measures of drainage basin (Sharma and Sarma, 2013).

GIS and RS techniques are proven convenient methods for morphometric characterization of sub-watersheds and prioritization of watersheds. As the satellite images provide a synoptic view of a large area, the RS and GIS methods become very useful in the analysis of drainage basin morphometry (Rai et al., 2017). Thus, the morphometric analysis using spatial techniques has emerged to be the fast and efficient method as compared to most of the conventional methods (Rao et al., 2010) such as manual extraction of drainage network and assigning the stream order from a published Survey of India topographic map. The present study aims at using remote sensing and GIS technology to compute various parameters of morphometric characteristics of the Chaliyar River basin.

Sensors onboard the satellite records the intensity of emitted or reflected electromagnetic radiations in the form of digital number (DN) for each pixel. These digital numbers can be transformed to more meaningful intensity units like radiance or reflectance. This process of conversion of digital numbers to radiance or reflectance is known as radiometric calibration. Sensor specific information is required to conduct radiometric calibration.

The Gujarat state is located on the north-west of India between 20^o6' N and 24^o42' N latitude and 60^o24' E to 74^o24' longitude. The climate of Gujarat is semi-arid tropical . the summers are very hot, the winter season is uncertain and irregular. The Arabian sea and Gulf of cambay have a moderating effect on the climate of the coastal areas of the state.

The state has a coastline of 1600 km (27% of the country) out of which Saurashtra and Kutch has about 1125 km long coastal line. The total coastal cropped area of the state is 8.75 lakh ha (9.11% of total cultivated area) spread over three agro-climatic regions of the state, out of which 91% comes under arid and semiarid climate type (Table 1). The important crops of the region are groundnut, bajara, sorghum, cotton, and wheat. The ground water availability is also scare. In the state recently the soil degradation through salinity has caught hold over 1.2 m ha of land, of which, about 0.3 m ha occurs in the coastal area. About 1125 km long coastal line is in Saurashtra and Kutch which comprises about 0.1079 m ha of saline land which needs to be treated for salinity reduction.
 

Introduction

Rainfall is a crucial component of the Earth’s climatic system that affects various aspects of human life. It has a direct impact on the ecosystems, water resources, agricultural production, and overall water management. Dependence on rainfall is particularly high in regions where it is the primary source of water, making it essential to have an accurate understanding of future rainfall patterns. Given its importance, rainfall forecasting is a critical concern for a wide range of stakeholders, including governments, businesses, risk management organizations, and the scientific community. However, predicting rainfall is a complex task as it is a random occurrence influenced by numerous factors (Samantaray et al., 2020). Even in similar weather conditions, the possibility of rainfall may vary. This makes historical data and predictive analytics crucial in forecasting future rainfall and taking necessary actions to manage its effects (Avinash et al., 2022). The impact of rainfall extends beyond water management to affect various human activities, including power generation, construction, tourism, and forestry, among others. Therefore, it is crucial to accurately forecast and analyze rainfall patterns to help mitigate the risks and consequences associated with it (Hernandez et al., 2016).

Rainfed agriculture constitutes 80% of global agriculture and plays a critical role in achieving global food security. However, growing world population, water scarcity, and climate change threaten rainfed farming through increased vulnerability to 1 droughts and other extreme weather events. Out of the total population of 7.3 billion, about 1 billion are food insecure and 60% of these live in South Asia and Sub Saharan Africa.

1. Monsoon: Types and Behavior in India

The monsoon is a dynamic and vital climatic phenomenon in India, playing a pivotal role in shaping the country’s weather patterns, agricultural practices, and overall water resource management. This seasonal shift in wind patterns brings about distinct wet and dry periods, impacting various regions differently. Understanding the types and behavior of the monsoon is essential for effective planning and adaptation to this critical aspect of India’s climate (fig 1).

Types of Monsoon in India

1. Southwest Monsoon (June to September)

The southwest monsoon is the lifeline of India’s agriculture, bringing the much needed rainfall that supports a majority of the country’s crops.

The great Indian epic ‘Ramayana’ says that ‘Lord Rama’ has tried to cross over the Bay of Bengal so as to reach Sri Lanka from India from three points along the southeastern fringe of the Indian coast. Firstly, he is said to have tried to cross from Vedaranniyam which is mythologically called as ‘Kodiyakkarai’ Secondly from Manamelkudi and finally crossed over to Sri Lanka from Rameswaram Island (Fig.1), as the former two coastal locations were widely separated from Sri Lanka by Bay of Bengal and the Rameswaram Island was nearer to Sri Lanka during that period. But, the recently acquired satellite data shows the huge accretion of sediments and rapid land building activity off Vedaranniyam coast (Fig. 2 and 3). The geomorphic interpretations carried out using IRS 1A imagery and 14^C archaeological dating of such geomorphic features have shown that such ongoing sediment accretion phenomena off vedaranniyam nose might in future connect the Vedaranniyam part of Indian Peninsula with Jaffna Peninsula of Sri Lanka if the sediment accumulation continues unabated. The sediment accretion in this area, therefore, requires detailed studies particularly in the context of the coastal ecosystem (Fig. 1).

Soil testing kit is developed to determine the available nutrient status of soil by rapid test methods. With this system of soil testing, a farmer can test his own soil as often and, in as many places as he feels necessary, and after gauging the need of his soil, he can apply the fertilizers as required. The present mode of soil testing in laboratories usually takes few days and sometime weeks and the farmers may have to travel long distances to submit the soil sample.

The crop growth and productivity is conditioned by many factors of which, the nutrient status (Content) of plant parts such as leaf, stem, etc play a critical role. Moreover the leaf and stem are considered as the indicator parts of plants for assessing the nutrients content of plant. Each crop plant requires the essential element at a specific concentration at different growth stages and it is known as ‘critical level’. When the nutrient content of plant depletes below the critical level the plants may exhibit some symptoms. The requirement or otherwise the availability of nutrients can be assessed by i) plant diagnosis ii) soil analysis and iii) plant analysis by two methods a) by qualitative test and b) by quantitative estimation. Based on the plant or soil tests, the required nutrients can be applied for crops to sustain the growth and rectify the deficiency disorders. The rapid tissue test would pave way for rectifying the nutritional problems for quick recovery, however the quantitative estimation of both plant and soil for nutrients concentration will be more useful and economic for applying fertilizers either as basal or foliar and would be the long term strategy to cope up with nutritional problems.

For rapid tissue test to assess the nutrient status, different parts of plant should be taken as indicator tissue and some of the representative crops are furnished below:

The satellite data is available in raster format. Raster data consists of two – dimensional array of pixels or grids which stores the values representing features. All the pixels are of same size and shape with their particular coordinate location. A raster data format is shown below.

The calculation of raster data statistics is very essential before performing some geoprocessing operations. Raster data statistics involve knowing the distribution of pixel values in a band, comparing the pixel values of two bands, extracting values of all bands for a particular geographical location or point, and computing statistics like mean, median, standard deviation, etc. at pixel level across all bands of raster dataset.

In R, codes to perform raster data statistics are present in raster package. The visualisation of raster data statistics can be done by rasterVis package. So, we need to import these packages in R in order to perform this exercise.

The chemistry of humic substances is the least comprehended in the field of Soil Science. The many important functions of humus will remain obscure if the structural chemistry of the humic and fulvic acids is not known. A variety of functional groups have been reported in humic substances. However, considerable disagreement still exists in respect of the exact amounts present and, in some cases, proof of existence is lacking.

Some important structural groups of organic molecules are given below:

1. Introduction
Soils stand out as an intricate and diverse ecosystem on our planet. Their significance extends beyond supplying 98.8% of the world’s food, encompassing a wide array of essential services such as carbon storage, regulation of greenhouse gas emissions, flood prevention, and offering support to burgeoning urban populations. However, it is crucial to recognize that soil is a finite natural resource. The unprecedented growth of the human population, escalating from 250 million in the year 1000 to 6.1 billion in 2000, with projections reaching 9.8 billion by 2050, along with the intensified practices of agricultural production, is exerting immense pressure on the sustainability of soils.
For long-term sustenance the concept of ‘Soil quality’ was propagated around three decades back from now in the United States of America, and further expanded to the scientists of European and Asian countries. Soil health and soil quality are two interweaving term that signifies the potentiality or capacity of soil towards mankind. These two words complement each other in such a way that one term automatically comes with another to determine both aspects i.e. agricultural sustainability and environmental quality in terms of plant, animal and human health (Haberern, 1992; Doran, 2002). Idowu et al. (2007) remarked that the term “soil quality” is more favoured by scientists, whereas “soil health” is a term favoured by farmers as it connotes a holistic approach to soil management. The inception and application of soil quality term was officially approved by Soil Science Society of America (SSSA). They defined soil quality as “The capacity of a specific kind of soil to function within natural or managed ecosystem boundaries, to sustain biological productivity, maintain environmental quality, and promote plant and animal health” as illustrated by Karlen et al. (1997). It is a complex composition of certain properties associated with physical (texture, bulk density, water holding capacity, infiltration capacity etc.), chemical (pH, EC, organic carbon, extractable macronutrient and micronutrient etc.) and biological (microbial activity and related parameters) conditions of soil (Prabha et al., 2020). There are primarily two key methodologies for assessing soil quality: the descriptive approach, which focuses on characterizing various aspects or attributes of soil quality, and the Indicative approach, which aims to identify the ability or capacity of an attribute in a desired manner. The comprehensive process of developing a soil quality index is guided by the 3-Is framework: the Identification of indicators, Interpretation, and Integration of selected soil quality indicators. It is important to note that the specific set of indicators utilized can vary between different soils, diverse agroecosystems, and from one crop to another. Additionally, climatic conditions and other abiotic factors may also significantly influence the assessment of soil quality.
The USDA has categorized soil quality indicators into four primary groups: visual, physical, chemical, and biological indicators. However, in the current context, the dominant indicators are physical, chemical, and biological. For a systematic assessment of soil quality, it is crucial to collect individual parameters and integrate them meaningfully. Consequently, integrated soil quality indicators

According to Planning Commission Report (2014), India generates about 62 million tons of municipal solid wastes (MSW) every year from urban cities. There has been a significant increase in municipal solid waste generation in India in the last few decades. This is largely due to rapid population growth and economic development in the country (Annepu, 2012). Solid waste management (SWM) has become a major environmental issue because of serious environmental implications like global warming (through green house gases emission) and contamination of toxic pollutants (like heavy metals) in surface and groundwater bodies. Solid waste management is one of the essential services to be provided by municipal authorities in the country to keep urban areas clean. Out of total waste generated in India, only 12.45% waste is scientifically processed and rest is disposed in open dumps (CPCB Report, 2013). Although, incineration of solid wastes is being followed in many places for energy production, composting is considered most environment friendly method of SWM as it promotes recycling of nutrients in crop production.

The following graph is a visual representation of how plant growth and/or yield is affected by nutrient concentrations

Introduction

Climate change is a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures. Eleven years from 1995-2006 rank among the twelve warmest years in the instrumental record of global surface temperature (since 1850). The 100-year linear trend (1906-2005) of 0.74 [0.56 to 0.92] °C is larger than the corresponding trend of 0.6 [0.4 to 0.8] °C (1901-2000) and over the 21st century average temperature of earth surface is likely to go up by an additional of 1.8-4°C (IPCC, 2007). This temperature increase can be attributed to the altered energy balance of the climate system resulting from changes in atmospheric concentrations of the green house gases (GHGs). Among the principal components of radiative forcing of climate change, CO₂ has the highest positive forcing leading to warming of climate. CO₂ has the least global warming potential among the major green house gases but due to its much higher concentration in the atmosphere; it is the major contributor towards global warming and climate change. Agriculture sector in India contributes 28% of the total GHG emissions (NATCOM, 2004). The global average from agriculture is only 13.5% (IPCC, 2007). In future, the percentage emissions from agriculture in India are likely to be smaller due to relatively much higher growth in emissions in energy-use transport and industrial sectors. The emissions from agriculture are primarily due to methane emissions from rice fields, enteric fermentation in ruminant animals and nitrous oxides from application of manures and fertilizers to agricultural soils (NATCOM, 2004).

Abstract

The Remote Sensing and the followed up field based investigations show that the Tamil Nadu coast, India, is facing series of geoenvironmental problems due to tectonic movements and morphodynamic processes. Such problems pose a challenge to the engineering geologists. The paper discusses such challenging engineering geological problems and plausible remedial measures.

Abstract

The ever increasing population in India and the world, impeding threats from the climate change scenario and the increasing demand for land resources from the industrial sector calls for improved resource efficiency. The production strategies are changing from input intensive to integrated resource management strategies. The shift is towards adopting the precision farming technologies like addressing the site specific variability and crop needs. Remote sensing technology coupled with GIS has been recognized as reliable tool in agriculture to guide application of fertilizer, pesticides and other farm inputs. With precision farming, technologies such as grid soil sampling, remote sensing, on- the-go sensing, and electronic yield monitoring help farmers gather very detailed information about the heterogeneous makeup of a farm field. Site specific applications means application of required input only where it is required rather than entire fields or adjusting application rates accordingly. This chapter discussed the input management based on the time of intervention - Input management prior to crop sowing, in season crop management and end of the season.

Keywords : Management zones, soil variability and Remote Sensing

Remote sensing and Geographic Information Systems provide spatial information for monitoring crops, land, soil and water resources. This chapter introduces their fundamental principles and explains developments involving satellites, UAVs, hyperspectral sensors, thermal imaging and cloud-based geospatial platforms. Analytical techniques include vegetation indices, time-series analysis, spatial modelling and artificial intelligence. Applications cover crop-health monitoring, yield forecasting, irrigation planning, drought assessment, pest and disease identification and soil-resource management. Integration with IoT, automation and other digital technologies improves the timeliness and resolution of agricultural information. These tools support evidence-based decisions responding to food-security, climate-change and natural-resource sustainability challenges.